Screw type filling mechanism for fountain pens



` F. KNIG 3,453,057 S-CREW TYPE FILLING MECHANISM FOR FOUNTAIN PENS July 1, 1969 Filed April 12, 1967 United States Patent O M 3,453,057 SCREW TYPE FILLING MECHANISM FOR FOUNTAIN PENS Fritz Knig, Quickborn, Germany, assignor to Montblanc- Simplo G.m.b.H., Hamburg, Germany Filed Apr. 12, 1967, Ser. No. 630,422 Int. Cl. B43k 5/06 U.S. 'Cl. 401-172 3 `Claims ABSTRACT OF THE DISCLOSURE This invention relates to a screw type filling mechanism for fountain pens.

More particularly, the invention is concerned with such filling mechanism for fountain pens, which comprises a piston or plunger reciprocable in and in axial direction of the ink reservoir by turning a member of a screw connection operatively connected to said piston. Screw type filling mechanisms for fountain pens of the general type set forth above are known in various designs. In this connection, and merely by way of example, U.S. Patent 3,154,055' may be mentioned.

According to another design of a screw type filling mechanism of the above-mentioned general character, there is provided a coupling bush fixed to a rotary cap and provided with a driving abutment for cooperation with a driven abutment on a propelling screw or spindle. The said driven abutment projects from the face of a coupling head forming a part of and located on the rear end of the propelling screw. A bearing ring locates the said driven coupling head and forms a rotary bearing for the coupling heads, while a telescopic sleeve which has an internal thread for cooperation with the propelling screw and which is externally guided in longitudinal slots in a guiding sleeve has its forward end carrying a filling plunger of the pen, which filling plunger is reciprocable in the ink reservoir of the pen in response to the turning of said propelling screw or spindle for filling said ink reservoir.

It is an object of this invention to simplify the construction and to reduce the cost of fabrication of the above-described filling mechanism.

It is a further object of the present invention so to simplify heretofore known constructions of the type in volVed as to eliminate the necessity of providing a bearing ring for the coupling head, to reduce the cost of assembly, and to connect the rotary cap and the coupling bush in a manner that will prevent any substantial relative rotation or axial displacement of said two members and yet permit their separation for individual replacement.

These and other objects of the present invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 is an axial section of a fountain pen having incorporated therein yfeatures of the present invention.

FIG. 2 is a cross-section taken on the line II-II in FIG. 1.

FIG. 3 is a side view of a coupling bush according to the invention, shown on a larger scale than that of FIG. 1.

FIG. 4 is a face end view of the coupling bush in FIG. 3, seen in the direction of the arrow A.

3,453,057 Patented July 1, 1969 ICC FIG. 5 is a face end view of the coupling head which engages the coupling bush.

The present invention consists primarily in a screw-type filling mechanism for a fountain pen including a propelling screw or spindle and a driving coupling which comprises a coupling bush mounted in a rotary cap and formed with a driving abutment for co-operation with a driven abutment on the propelling screw, movement of the propelling screw being adapted to effect operation of a filling element of the pen. The invention is characterized primarily in that the rear end of the rotary cap has a rearwardly open bore substantially corresponding in length and diameter to the size of the coupling bush, and that the coupling bush consists of an elastically flexible material and is provided with a slot in its free edge and with radial projections extending outwardly beyond the diameter of the bush and adapted to engage corresponding recesses in the rotary cap.

According to a preferred embodiment of the invention, the radial projections may be of claw-like configuration, and the recess in the rotary cap may be created by a shoulder-forming enlargement of the bore in the rotary cap.

According to another feature of the invention, at the level of the shoulder-forming enlargement, there is provided a floor in the rotary cap which is formed with an opening for the passage therethrough of the radial projections of the coupling bush and of the shaft of the propelling screw, thereby preventing the coupling bush from rotating inside the rotary cap and preventing the propelling screw, which is provided with the coupling head, from moving axially to any substantial extent.

The screw type filling mechanism illustrated in FIG. 1 is provided at its rear end with a rotatable cap 3' which, in a manner to be hereinafter described in greater detail, contains a coupling bush 23 rotatably fixed in the cap and prevented from moving axially.

The `coupling b-ush 23 is formed with a driving abutment 5 and at the same time forms a bearing for a coupling head 8 which is provided with a driven abutment 9 adapted to co-operate with the driving abutment 5 of the coupling bush 23.

The coupling head 8 forms the rear end of a propelling screw 13 provided with an outer helical thread 12 engaging a co-operating internal helical thread 14 in a telescopically propelled sleeve 15. The telescopic sleeve 15 is guided by externally formed axially parallel fins riding in longitudinal slots and is therefore axially movable but cannot rotate. Sleeve 15 has connected thereto a filling plunger 15a.

For the purpose of simplifying the assembly, and in order to reduce the number of necessary parts, the coupling bush 23 has a downward extension in the form of an elastically compressible slotted skirt. The bottom free edge of the skirt has claw-shaped radial projections 24 which extend beyond the diameter of the Coupling bush (FIG. 4). The slots 28 which are cut into the skirt of the coupling bush 23 facilitate radial compression sufficiently to permit its insertion from the top end into the internal bore of the rotary cap, despite the presence of the projecting claws 24. When fully inserted, in the position illustrated in FIG. 1, the radially projecting claws 24 snap into engagement with the underside of an internal annular shoulder inside the rotary cap 3.

In the plane of the annular shoulder, the rotary cap 3 is formed with a divided floor 25 which provides a passage for the propelling shaft 13 but not for the head 8, and which thus prevents any substantial movement in the axial direction of the propelling shaft 13 relative to the Vcap 3. Moreover, the circular segmental shape of the 3 exact width to fill the gap 26 between the two halves of the floor 25.

For assembling the mechanism it is necessary first to insert the propelling screw 13 through the rear end of the rotary cap 3 so that its head rests upon the fioor 25. Now also the coupling bush 23 is inserted through the rear end of the cap 3 in a position in which the abutment 9 of the head 8 may engage the bottom recess of the bush 23 adjacent to its abutment 5. During this insertion the projecting claws 24 of the bush 23 are yieldably forced inwardly until they may return to their normal position shown in FIG. 1. In this position the shaft 13 is held axially immovable, however, it may perform a restricted rotation in relation to the rotary cap 3.

The screw mechanism according to the invention is particularly easy and cheap to manufacture. Since none of the parts is adhesively bonded the mechanism can be dismantled at any time with the aid of a suitable tool.

It is, of course, to be understood that the present invention is, by no means limited to the particular embodiment set forth above, but also comprisees any modifications within the scope of the appended claims.

What I claim is:

1. For use in connection with a fountain pen having a barrel with an ink reservoir therein and a filling piston reciprocable in said ink reservoir and also having a hollow inwardly threaded member operatively connected to said piston; a rotatable cap forming a tubular member for rotatable connection with the barrel of a fountain pen, said tubular member having an axial bore therethrough comprising an outer bore section and an inner bore section defining shoulder means with said outer bore section, said tubular section also having transverse partition wall means located in said axial bore and separating said bore sections from each other, said transverse partition wall means having a slot therethrough the length of which approximately equals the diameter of that axial bore portion which is adjacent said transverse wall, bushing means arranged in said first bore section and having end wall means near the outer end of said outer bore section and having two oppositely located radially outwardly extending resilient projections engaging said shoulder means, the resiliency of said projections permitting temporary bending thereof inwardly for passage through said slot of said partition wall means, and a rotatable threaded spindle for threaded engagement with the hollow inwardly threaded member of a fountain pen, said spindle having a head confined between said outer end wall means of said cap and said partition wall means so as to prevent said spindle from carrying out any material axial movement in said cap, said spindle head and said cap respectively being provided with abutment means operable to engage each other for imparting a rotary movement upon said spindle in either direction in conformity with the direction of rotation of said cap.

2. An arrangement according to claim 1, in which the outer periphery of said projections tapers in the direction away from said end wall means.

3. An arrangement according to claim 1, in which said projections are of claw-shaped configuration.

References Cited UNITED STATES PATENTS 2,167,8l5 8/1939 Rsler et al 401-174 2,258,841 10/1941 Biro 401-172 3,154,055 10/1964 Lawton 401-172 FOREIGN PATENTS 1,026,662 9/ 1958 Germany.

LAWRENCE CHARLES, Primary Examiner.

U.S. C1. X.R. 401-174 

